Publications

Abstract

Is visual reinterpretation of bistable figures (e.g., duck/rabbit figure) in visual imagery possible? Current consensus suggests that it is in principle possible because of converging evidence of quasi-pictorial functioning of visual imagery. Yet, studies that have directly tested and found evidence for reinterpretation in visual imagery, allow for the possibility that reinterpretation was already achieved during memorization of the figure(s). One study resolved this issue, providing evidence for reinterpretation in visual imagery (Mast and Kosslyn, Cognition 86:57-70, 2002). However, participants in that study performed reinterpretations with aid of visual cues. Hence, reinterpretation was not performed with mental imagery alone. Therefore, in this study we assessed the possibility of reinterpretation without visual support. We further explored the possible role of haptic cues to assess the multimodal nature of mental imagery. Fifty-three participants were consecutively presented three to be remembered bistable 2-D figures (reinterpretable when rotated 180 degrees), two of which were visually inspected and one was explored hapticly. After memorization of the figures, a visually bistable exemplar figure was presented to ensure understanding of the concept of visual bistability. During recall, 11 participants (out of 36; 30.6%) who did not spot bistability during memorization successfully performed reinterpretations when instructed to mentally rotate their visual image, but additional haptic cues during mental imagery did not inflate reinterpretation ability. This study validates previous findings that reinterpretation in visual imagery is possible.

Abstract

In two experiments, we examined the role of gesture in reinterpreting a mental image. In Experiment 1, we found that participants gestured more about a figure they had learned through manual exploration than about a figure they had learned through vision. This supports claims that gestures emerge from the activation of perception-relevant actions during mental imagery. In Experiment 2, we investigated whether such gestures have a causal role in affecting the quality of mental imagery. Participants were randomly assigned to gesture, not gesture, or engage in a manual interference task as they attempted to reinterpret a figure they had learned through manual exploration. We found that manual interference significantly impaired participants' success on the task. Taken together, these results suggest that gestures reflect mental imaginings of interactions with a mental image and that these imaginings are critically important for mental manipulation and reinterpretation of that image. However, our results suggest that enacting the imagined movements in gesture is not critically important on this particular task.

Abstract

Gesture–speech synchrony re-stabilizes when hand movement or speech is disrupted by a delayed
feedback manipulation, suggesting strong bidirectional coupling between gesture and speech. Yet it
has also been argued from case studies in perceptual–motor pathology that hand gestures are a special
kind of action that does not require closed-loop re-afferent feedback to maintain synchrony with
speech. In the current pre-registered within-subject study, we used motion tracking to conceptually
replicate McNeill’s (1992) classic study on gesture–speech synchrony under normal and 150 ms
delayed auditory feedback of speech conditions (NO DAF vs. DAF). Consistent with, and extending
McNeill’s original results, we obtain evidence that (a) gesture-speech synchrony is more stable
under DAF versus NO DAF (i.e., increased coupling effect), (b) that gesture and speech variably
entrain to the external auditory delay as indicated by a consistent shift in gesture-speech synchrony
offsets (i.e., entrainment effect), and (c) that the coupling effect and the entrainment effect are codependent.
We suggest, therefore, that gesture–speech synchrony provides a way for the cognitive
system to stabilize rhythmic activity under interfering conditions.

Abstract

Spontaneously occurring speech is often seamlessly accompanied by hand gestures. Detailed
observations of video data suggest that speech and gesture are tightly synchronized in time,
consistent with a dynamic interplay between body and mind. However, spontaneous gesturespeech
synchrony has rarely been objectively quantified beyond analyses of video data, which
do not allow for identification of kinematic properties of gestures. Consequently, the point in
gesture which is held to couple with speech, the so-called moment of “maximum effort”, has
been variably equated with the peak velocity, peak acceleration, peak deceleration, or the onset
of the gesture. In the current exploratory report, we provide novel evidence from motiontracking
and acoustic data that peak velocity is closely aligned, and shortly leads, the peak pitch
(F0) of speech

Abstract

The split-attention effect entails that learning from spatially separated, but mutually referring information
sources (e.g., text and picture), is less effective than learning from the equivalent spatially integrated
sources. According to cognitive load theory, impaired learning is caused by the working memory load
imposed by the need to distribute attention between the information sources and mentally integrate them.
In this study, we directly tested whether the split-attention effect is caused by spatial separation per se.
Spatial distance was varied in basic cognitive tasks involving pictures (Experiment 1) and text–picture
combinations (Experiment 2; preregistered study), and in more ecologically valid learning materials
(Experiment 3). Experiment 1 showed that having to integrate two pictorial stimuli at greater distances
diminished performance on a secondary visual working memory task, but did not lead to slower
integration. When participants had to integrate a picture and written text in Experiment 2, a greater
distance led to slower integration of the stimuli, but not to diminished performance on the secondary task.
Experiment 3 showed that presenting spatially separated (compared with integrated) textual and pictorial
information yielded fewer integrative eye movements, but this was not further exacerbated when
increasing spatial distance even further. This effect on learning processes did not lead to differences in
learning outcomes between conditions. In conclusion, we provide evidence that larger distances between
spatially separated information sources influence learning processes, but that spatial separation on its
own is not likely to be the only, nor a sufficient, condition for impacting learning outcomes.